The invention concerns a filter cigarette whose filter is surrounded by a filter wrapping paper which is enclosed by a tip layer, wherein an interior of the filter wrapping paper is coated with metal, in particular aluminum.
Development of cigarettes with reduced smoke constituents, in particular nicotine, condensate and carbon monoxide, has globally been driven forward by statutory regulations, a higher level of consumer acceptance and increased awareness of health.
Usually, cigarette papers which are highly permeable to air and burning-friendly are used for production of cigarettes with reduced smoke constituents, and a cigarette filter has been additionally vented by a perforated zone in a tip layer. Both technical measures dilute a main smoke flow by virtue of secondary air, and thereby reduce a level of concentration of smoke constituents. Use of filter material with a high retention action and a high draw resistance also causes a reduction in smoke constituents, but encounters limitations in terms of acceptance by consumers.
In the state of the art, DE 3038093 A1, WO 89/03183 A1 and CH 343865 disclose cigarette filters in which metal is introduced into the filter. That, however, on the one hand involves a considerable increase in expenditure in manufacture of filters, while on the other hand an effect achieved thereby is only very vaguely described with regard to its effect.
Therefore, a basic starting point adopted by the invention is a filter cigarette whose filter is surrounded by a filter wrapping paper which is enclosed by a tip layer, wherein air can penetrate into the filter through the filter wrapping paper. In accordance with the invention a coating is applied only on a part of the filter wrapping paper so that air can penetrate through the wrapping paper into the filter.
A metalization effect can be implemented by application in particle form, and/or by suitable application of flat patterns, to the wrapping paper on a surface of the paper, but not by complete coating of the filter wrapping paper. Surprisingly, partial coating of the filter wrapping paper with metal causes a selective reduction in carbon monoxide content of a main smoke flow.
Further features and details of the present invention will be apparent from its specific description hereinafter.